Functions Question 187
Question: $ \underset{x\to \pi /2}{\mathop{\lim }},[ x\tan x-( \frac{\pi }{2} )\sec x ]= $
Options:
A) 1
B) ?1
C) 0
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
$ \underset{x\to \pi /2}{\mathop{\lim }}[ x\tan x-( \frac{\pi }{2} ),\sec x ] $ $ =\underset{x\to \pi /2}{\mathop{\lim }},\frac{2x\sin x-\pi }{2,\cos x} $ , $ [ form\frac{0}{0} ] $ $ =\underset{x\to \pi /2}{\mathop{\lim }},\frac{[2,\sin x+2x\cos x]}{-2,\sin x}=-1 $ ,(By L-Hospital?s rule).
BETA
